Hi Christopher,
I can't quite nut this one out, but you can't just have ##f sitting in the open between scores - it's a bad _expression_. You can't place in that location a variable referring to an _expression_ that has a boolean as its evaluation.
You can have markup between scores, so if you make this change it will work:
titleFootnotes = \markup { \null }
I don't use these earlier versions of lilypond so I am unable to comment on when and why the syntax/semantics may have changed.
But it seems to me what you want is conditional inclusion. There's a lot of discussion about this on the list. Search the archives.
Andrew